A Texas man who was arrested for waving a sign to warn drivers of a lurking traffic cop defended himself in a court by saying his warning was "the same thing as a speed limit sign."

Ron Martin, 33, appeared in court Wednesday to fight a misdemeanor charge of waving a homemade sign.

He was arrested last October after Police Officer Thomas Mronzinski saw him on the median strip of a six-lane highway holding up the sign – he is a sign painter by trade – reading "Police Ahead."

The officer first had his suspicions that Martin was in the area as he sat in his unmarked police car on Eldorado Parkway in Frisco, Texas.

"I observed a couple of cars drive by traveling westbound waving at us," Mronzinski wrote in his arrest report. "Mr. Martin has a history with the Frisco Police Department Officers in holding signs in the center median of traffic stating 'police ahead.'"

A colleague had also radioed earlier that morning to warn Mronzinski that he had seen Martin in the area.

Mronzinski wrote in the report that as he approached, Martin began videotaping the arrest on his phone. After a number of requests to drop the sign, Martin complied and Mronzinski, along with another officer he had radioed for backup, were able to handcuff Martin and take him into custody.

Mronzinski also wrote he had seen Martin conducting similar activities two times that month, and that in one instance Martin "was running back and forth in the center median holding a sign."

Martin told the court that by displaying the warning, ultimately he was trying to do the same job as law enforcement and encourage people (and officers) to driver more slowly.

"I just don't wear a uniform," Martin testified. "I'm the same thing as a speed limit sign, just reminding people that there is a limit here."

"I think it's absolutely important for officers to be on the streets and enforce laws," he said.

Texas does not have laws banning people from warning drivers about speed traps. Police instead cited the city's ordinance that states that people holding or wearing signs for advertising must be on private property.

Martin was in the median strip when he was arrested, but has pleaded not guilty to his Class C misdemeanor charge, arguing that he was not advertising anything at the time of arrest.

Frisco Police Department spokesman Sgt. Brad Merritt told ABC News that a Class C misdemeanor is "basically a traffic ticket," but said police would not comment further pending the outcome of the case, which is scheduled for court on Feb. 21.

Police periodically crack down on people warning motorists about speed traps.

In July 2012, Houston police arrested a Natalie Plummer for holding a sign made out of a paper grocery bag that read "Speed Trap!" She was slapped with a misdemeanor for "walking in the roadway where there is a sidewalk present."

Laws concerning methods of alerting motorists to police presence vary across the country. The most popular way - flashing headlights to oncoming traffic - is legal in some states, but not others.

Laws in New Jersey, New York, Ohio, Pennsylvania, Tennessee, Virginia and Florida allow headlight flashing, while other states, such as Arizona and Alaska, forbid it. In Washington, drivers may be fined $124 for flashing their high beams within 400 feet of another vehicle for any reason.

Last July, a Missouri man sued the city after receiving a ticket for violating a local law against flashing lights on certain kinds of vehicles, while in May 2012, a Florida judge ruled that a man arrested for flashing his headlights was exercising his freedom of speech under the First Amendment.